@article{910bc19aabc340248043e947166b97a5,
title = "Nonparametric estimation of median survival times with applications to multi-site or multicenter studies",
abstract = "We propose a nonparametric shrinkage estimator for the median survival times from several independent samples of right-censored data, which combines the samples and hypothesis information to improve the efficiency. We compare efficiency of the proposed shrinkage estimation procedure to unrestricted estimator and combined estimator through extensive simulation studies. Our results indicate that performance of these estimators depends on the strength of homogeneity of the medians. When homogeneity holds, the combined estimator is the most efficient estimator. However, it becomes inconsistent when homogeneity fails. On the other hand, the proposed shrinkage estimator remains efficient. Its efficiency decreases as the equality of the survival medians is deviated, but is expected to be as good as or equal to the unrestricted estimator. Our simulation studies also indicate that the proposed shrinkage estimator is robust to moderate levels of censoring. We demonstrate application of these methods to estimating median time for trauma patients to receive red blood cells in the Prospective Observational Multi-center Major Trauma Transfusion (PROMMTT) study.",
author = "Rahbar, {Mohammad H.} and Sangbum Choi and Chuan Hong and Liang Zhu and Sangchoon Jeon and Gardiner, {Joseph C.}",
note = "Funding Information: This research is co-funded by the National Heart, Lung and Blood Institute (NHLBI R21 HL109479) and by the U.S. Army Medical Research and Materiel Command (subcontract W81XWH-08-C-0712), awarded to The University of Texas Health Science Center at Houston (UTHealth). This research is also partly supported by the NIH Centers for Translational Science Award (NIH CTSA) grant (UL1 RR024148), awarded to the Center for Clinical and Translational Sciences (CCTS) in UTHealth by the National Center for Research Resources (NCRR) and its renewal (UL1 TR000371) by the National Center for Advancing Translational Sciences (NCATS). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NHLBI, NCATS or the U.S. Army. This research is co-funded by the National Heart, Lung and Blood Institute (NHLBI R21 HL109479) and by the U.S. Army Medical Research and Materiel Command (subcontract W81XWH-08-C-0712), awarded to The University of Texas Health Science Center at Houston (UTHealth). This research is also partly supported by the NIH Centers for Translational Science Award (NIH CTSA) grant (UL1 RR024148), awarded to the Center for Clinical and Translational Sciences (CCTS) in UTHealth by the National Center for Research Resources (NCRR) and its renewal (UL1 TR000371) by the National Center for Advancing Translational Sciences (NCATS). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NHLBI, NCATS or the U.S. Army. Publisher Copyright: {\textcopyright} 2018 Rahbar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.",
year = "2018",
month = may,
doi = "10.1371/journal.pone.0197295",
language = "English",
volume = "13",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "5",
}